Patent Expiration, Pediatric Exclusivity, and Generic Drug Approval – Some Interesting Tensions Between the FDC Act and Patent Law

By Kurt R. Karst –   

When does a patent expire?  When does pediatric exclusivity begin and end?  And when can FDA approve ANDAs (or 505(b)(2) applications)?  These are some interesting questions touched on in some recent court decisions.  But before we get to those cases, some law . . . .  

The patent statute at 35 U.S.C. § 154(a)(2) (post-GATT/URAA) states the following with respect to the term of a patent: “Subject to the payment of fees under this title, such grant shall be for a term beginning on the date on which the patent issues and ending 20 years from the date on which the application for the patent was filed in the United States.”  So, does a patent expire 20 years from filing, or is it 20 years plus one day?  Apparently, the answer is 20 years plus one day – as alluded to in various Patent and Trademark Office decisions on maintenance fee payment issues (here, here, and here) providing that a patent expires at midnight on the date of expiration.  Nevertheless, we note that FDA’s longstanding practice is to approve ANDAs on the patent expiration date specificed in the Orange Book – i.e., on the date that is 20 years from patent filing and not 20 years plus one day.  (This is consistent with how FDA treats the expiration of non-patent market exclusivity, where the periods listed in the Orange Book do expire on the date listed.)

With respect to generic drug approval, the patent statute at 35 U.S.C. § 271(e)(4)(A) states that “the court shall order the effective date of any approval of the drug or veterinary biological product involved in the infringement to be a date which is not earlier than the date of the expiration of the patent which has been infringed” (emphasis added).  In addition, for an ANDA (or a 505(b)(2) application) containing a Paragraph III certification, the FDC Act at § 505(j)(5)(B)(ii) states that “the approval shall be made effective on the date certified under [FDC Act § 505(j)(2)(A)(vii)(III)],” which is “the date on which such patent will expire” (emphasis added).  These provisions are consistent with FDA’s approval practices.

The pediatric exclusivity provisions at FDC Act § 505A add a wrinkle to the approval equation.  They provide that pediatric exclusivity applies to an Orange Book-listed patent covering a Reference Listed Drug such that FDA is prevented from approving an ANDA (or a 505(b)(2) application) containing a Paragraph II or a Paragraph III certification to such Orange Book-listed patent, or a Paragraph IV certification to such Orange Book-listed patent that a court has determined is valid and would be infringed, until “six months after the date the patent expires (including any patent extensions)” (emphasis added).

So, taking pediatric exclusivity out of the approval equation, FDA can approve an ANDA on the date of patent expiration listed in the Orange Book rather than on the day after patent expiration.  But including pediatric exclusivity in the approval equation could, some might argue, yield a different result – FDA approval on the day after expiration. 

(Interestingly, the tension between patent expiration and FDA approval was not resolved with respect to biosimilars in the Patient Protection and Affordable Care Act.  New 35 U.S.C. § 271(e)(4)(D) provides that:

the court shall order a permanent injunction prohibiting any infringement of the patent by the biological product involved in the infringement until a date which is not earlier than the date of the expiration of the patent that has been infringed under paragraph (2)(C), provided the patent is the subject of a final court decision, as defined in section 351(k)(6) of the Public Health Service Act, in an action for infringement of the patent under section 351(l)(6) of such Act, and the biological product has not yet been approved because of section 351(k)(7) of such Act. [(emphasis added)]

An earlier biosimilars legislative proposal sponsored by Rep. Anna Eshoo (D-CA) would have provided that FDA “shall make approval of the application effective on the day after the date of expiration of the patent that has been found to be infringed.  If more than one such patent is found to be infringed by the court, the approval of the application shall be made effective on the day after the date that the last such patent expires” (emphasis added).)

Now on to the cases . . . .

In an unpublished November 2009 decision from the U.S. District Court for the District of Delaware concerning the approval of a generic version of the acid reflux drug PREVACID (lansoprazole), the court ordered that the “effective date of any [FDA] approval of [certain ANDAs] shall be no later than November 11, 2009” – the day after the period of pediatric exclusivity applicable to U.S. Patent No. 4,628,098 (“the ‘098 patent”) listed in the Orange Book expired.  The court also clarified that “November 11, 2009 is the earliest effective date” upon which a generic applicant “may launch its commercial generic product.”  In what appears to be a case of first impression, the court issued its decision after the NDA holder, Takeda, argued in a Motion for Clarification of Final Judgment Order that the court’s previous ruling that ANDA approval “shall be no earlier than the date of expiration of claim 10 of the ‘098 patent and any pediatric exclusivity that applies to the ‘098 patent, if applicable,” needed greater clarity and could lead to ANDA approval and launch of the generic product one day too early – on November 10, 2009.

Citing the pediatric exclusivity provisions at FDC Act § 505A (i.e., ANDA approval shall not occur until “six months after the date the patent expires (including any patent extensions)”), Takeda argued that “the Orange Book captures the time period for which the FDA is barred from approving an ANDA; that period runs up to and through the date of expiration of the patent extension, in this instance, November 10, 2009.”  Although, the court’s Order reflected the November 11, 2009 date, FDA nevertheless approved an ANDA on November 10, 2009.  (Consistent with the court’s order, the generic version was presumably not launched until November 11, 2009.)

Two other recent court decisions – one concerning generic VIGAMOX (moxifloxacin HCl) and another concerning generic PROTONIX (pantoprazole sodium) – reached similar conclusions, although the decisions do not specifically grapple with the approval date issue as in the generic PREVACID case.  In the generic VIGAMOX case, Judge Sue L. Robinson of the U.S. District Court for the District of Delaware (the same Judge who issued the November 2009 generic PREVACID decision) ruled, apparently sua sponte, in an August 5, 2010 decision that FDA could not approve an ANDA until March 30, 2020, the day after pediatric exclusivity applicable to U.S. Patent No. 6,716,830 (“the ‘830 patent”) expires.  (The ‘830 patent is listed in the Orange Book with pediatric exclusivity expiring on March 29, 2020.)  And in a decision issued last week by Judge Jose L. Linares of the U.S. District Court for the District of New Jersey, the court ordered that the date of approval of a particular ANDA for generic PROTONIX  “shall be a date which is not earlier than January 20, 2011, the first day after the date on which Plaintiffs’ pediatric exclusivity period [with respect to U.S. Patent No. 4,758,579 (‘the ‘579 patent’)] ends” (emphasis added).  (The ‘579 patent is listed in the Orange Book with pediatric exclusivity expiring on January 19, 2011.) 

FDA has not yet been asked to opine on how the Agency’s ANDA (and 505(b)(2) application) approval practices mesh with the patent laws and the FDC Act’s various  provisions affecting generic drug approval.  And although there are, as explained above, some cases applying the pediatric exclusivity provisions of the FDC Act, we are not aware of a case challenging generic drug approvals without the involvement of pediatric exclusivity – that is, a challenge touched off by 35 U.S.C. § 271(e)(4)(A) and the term provisions of the patent laws.